#2 Foundation and Architecture: Why Design a New Programming Language? -> Motivation Behind Creating New Programming Languages

In the rapidly evolving domain of computer science and software engineering, the creation of a new programming language is not merely an academic exercise or a vanity project. It is often a response to real limitations in existing tools, a push for innovation, or a necessity dictated by emerging domains, hardware capabilities, or architectural patterns. Over the last five years, the resurgence in language design—particularly those inspired by the C tradition—has been fueled by a complex interplay of technological, practical, and philosophical motivations.

This section explores the concentrated motivations for designing a new programming language, particularly one that aligns with C-style syntax and semantics, while leveraging the expressiveness, safety, and abstraction capabilities introduced in C++20 and C++23.

1. Addressing Limitations in Existing Languages

Despite the dominance of legacy languages like C, C++, and Java, modern software demands have exposed their deficiencies in various areas:

• Safety and Undefined Behavior: C and early C++ place performance above safety, leaving programmers vulnerable to undefined behavior, memory corruption, and data races. Designing a new language allows you to enforce compile-time guarantees without sacrificing system-level control.

• Verbosity and Boilerplate: Even with C++17 and prior standards, writing expressive, reusable code often involved excessive boilerplate. C++20 introduced concepts, ranges, and coroutines to combat this, inspiring newer languages and tools to reimagine simpler syntaxes and workflows.

• Concurrency Models: Traditional languages provide limited abstractions for safe and ergonomic multithreading. With the emergence of std::jthread, atomic smart pointers, and semaphores in C++20/23, we now have the vocabulary to reimagine concurrency as a first-class citizen in language design.

2. Integration of Modern Language Features with Lower-Level Control

Many recent systems-level languages (like Rust or Zig) aim to balance high-level abstraction with low-level control, but their syntax or compiler complexity might be off-putting for developers from C-style backgrounds.

Designing a new C-style language that leverages modern C++ internals (via modules, constexpr, template metaprogramming, and ranges) gives the designer the opportunity to:

• Provide compile-time reflection and introspection

• Enable efficient deterministic memory handling without garbage collection

• Build powerful DSLs using C++20 constexpr evaluators

• Enforce user-defined safety contracts via concepts and static assertions

A custom language interpreter written in modern C++ allows tight control over performance, parsing strategies, and the ability to evolve faster than general-purpose compilers.

3. Domain-Specific Needs and Embedded Use-Cases

Many new programming languages are born to serve specialized industries:

• Embedded systems

• Robotics and IoT

• High-frequency trading

• Scientific simulation and GPU programming

A general-purpose language may fail to offer concise constructs for these use-cases. By creating a new language, designers can provide:

• Custom data types for hardware representation

• Deterministic memory layouts and zero-cost abstractions

• Inline real-time constraints and timing models

• Platform-aware syntax that maps closely to hardware registers or signals

C++23 features like constexpr dynamic allocation and std::span now allow better memory views and compile-time memory modeling, which can be leveraged in a new language runtime or interpreter.

4. Pedagogical and Research Objectives

Another clear motivation is educational clarity. Language design exposes students and professionals to compilers, parsers, runtime models, and systems architecture in a unified, project-based framework. Creating a new language helps reinforce foundational CS concepts:

• Lexical analysis and syntax trees

• Semantic resolution

• Intermediate representations

• Memory models and garbage collection algorithms

• Just-in-time (JIT) vs Ahead-of-Time (AOT) compilation

Using modern C++ (especially ranges, variant, and coroutines), a full-featured interpreter can be implemented in a way that is modular, readable, and maintainable, turning abstract theory into concrete working code.

5. Experimentation and Language Innovation

Language design is often a space for experimentation—trying new models for:

• Error handling (optional types, monads, or result types)

• Immutability and purity

• Pattern matching and algebraic data types

• Macros or compile-time metaprogramming

• Customizable syntax and infix operators

While traditional C++ is bound by backward compatibility, a new language can embrace new paradigms without legacy constraints. C++20 and C++23 provide all necessary tools to build and test these concepts rapidly:

• consteval and constinit for compile-time execution

• Advanced template constraints via requires and concepts

• Lambda improvements and pipeline expressions with ranges

• Pattern-based traversal using std::visit on std::variant

6. Performance Transparency and Predictability

In modern computing, predictable performance is as important as raw speed. A major reason behind new language creation is to avoid the opacity of runtime optimizations, GC pauses, or unexpected heap allocations.

A new language—especially when implemented in modern C++—can guarantee:

• Explicit stack vs heap allocation rules

• Fine-grained control over function inlining and tail calls

• Trivially destructible or relocatable types

• Custom ABI rules tailored for interop or hardware targets

Using C++20/23’s [[no_unique_address]], improved constexpr capabilities, and std::bit_cast, developers can build transparent, efficient data movement strategies directly into the language runtime.

7. Cultural and Ecosystem Reset

Some motivations are philosophical rather than technical. A new language offers a cultural reset, stripping away decades of accumulated legacy and forcing a rethinking of best practices.

By setting new defaults—immutability, safety, module-based encapsulation, strong typing—designers can influence coding culture from the ground up. Combined with C++ modules (introduced in C++20), this facilitates a modern build system and package manager, avoiding the traditional pitfalls of header-based dependency hell.

Conclusion

The motivation to design a new programming language stems from a deep desire to improve expressiveness, safety, and performance while removing the friction caused by legacy constraints. With the maturity of C++20 and C++23, developers are uniquely positioned to create performant, readable, and maintainable language tools, interpreters, and runtimes that not only demonstrate engineering precision but also serve as a launching pad for language innovation. By building on modern C++’s powerful metaprogramming, memory safety aids, and concurrency features, the creation of a new C-style language is no longer a monumental task—but a rewarding exploration of the very essence of software design.